Acidulation of food masses has been accomplished by various means. One method, of long standing, was to inoculate the food mass with a small proportion of previously-fermented food mass. The resulting inoculated food mass was allowed to ferment for an extended period of time. Fermentation by this method was gradual due to the time needed for bacteria to grow and produce acid, usually lactic acid.
Another method for acidulating a food mass was for food acids to be added directly to the food. In food masses of meat or meat products, especially comminuted meat products, localized high concentrations of acid from the particulate acidulant must be avoided. These high acid concentrations or so-called "hot spots" can deleteriously affect the appearance and/or taste of the meat being processed and eventually the finished goods also. The handling characteristics of the meat mass are also changed to that of such a hardness that it is no longer easy to stuff the comminuted meat into casings if this is desired. Also, a meat emulsion can "short out" or "grease out" whereby emulsified fat escapes from its usually high proteinaceous coating if the protein fiber is degraded before it has been hardened by smoking.
To avoid degradation of the food mass from localized high concentrations of such acid, dispersion (throughout the food mass) had to be quickly accomplished. A variation of this approach was to add a substance such as glucono delta lactone, which required further reaction with the food mass before acid developed. Most commonly such an acidulant reacted with water present in the food and hydrolyzed into acid. This is shown in U.S. Pat. No. 2,992,116 (Louis Sair) and British Pat. No. 1,138,765, published Jan. 1, 1969. However, the dispersion still had to be relatively quick to avoid problems with concentrations of acid produced from undispersed concentrations of acid-producing substances.
Finally, some acidulants have been encapsulated with a layer of an edible lipid or wax, such as disclosed in Meusel et al U.S. Pat. No. 3,359,120. The layer of fat, by reducing or totally preventing until later the contact of the acidulant with the food mass, allowed a longer period for dispersion of the particulates. Bohren U.S. Pat. No. 3,793,465 disclosed an acid compound with controlled release, for acidifying milk, comprising an acid such as citric or lactic, on a solid carrier such as glucose, sucrose or protein, coated with an edible fat. Westreich et al U.S. Pat. No. 4,220,668 also is of interest, disclosing soaking of meat products in a solution of lactic acid, with or without other acids.
The use of lactic acid for acidulating meat products, over other acids, is preferred because it produces the same texture, preservation and tangy flavor obtained with natural fermentation, using a bacterial starter culture. However, lactic acid is normally in a liquid state and its use for meat acidulation has been accompanied with substantial difficulties. In the Westreich et al process, it was necessary to use for the meat emulsion mixture a casing which was permeable to acids, severely limiting the flexibility of the process.
Lactic acid in crystalline form is very deliquescent and when exposed to atmosphere quickly liquifies. It has thus been impossible to use crystalline lactic acid for meat acidulation.
A principal problem experienced with plating lactic acid onto a carrier has been obtaining a sufficient concentration of lactic acid for effective acidulation, taking into consideration the fact that the carrier, whatever water is present, and coating fat are diluents in the meat acidulation process. In addition, the carrier has to have a proper surface area to volume (low surface area) to obtain an effective fat coating, i.e., minimal leach of acid, without an excessive amount of coating. In the Bohren patent the only ratios given for a lactic acid/carrier/lipid product is in Example 3, wherein the product comprises about 22.5% lactic acid, 25% glucose, and 50% lipid.
With less than 25% acid, so large an amount of the plated, coated product would be needed for the acidulation of meat process (e.g., about four pounds of product to get one pound of acid) as to render the process less than cost effective.
In addition to the carriers proposed in the Bohren patent, namely glucose, sucrose or protein, it has also been proposed to use such carriers as sodium silicoaluminate and microcrystalline cellulose (Avicel PH-101, marketed by FMC Corporation). These are known anti-caking agents of fine particle size (high surface area to volume ratio) and capable of absorbing a fair amount of lactic acid. However, it was found that they could not be effectively fat coated, even with the use of an excessive amount of fat, possibly because of the particle size and possibly because of an irregular particle shape.
Advantages of the instant acidulant and process using the same are that a high concentration of lactic acid dispersed in the food mass being acidulated can be obtained, while at the same time effective protection against localized high acid concentrations, or so-called "hot spots" in meat products, can also be obtained. The reason for this is that the calcium lactate was found to be a particularly suitable carrier. Not only is it capable of absorbing more lactic acid, e.g., 100% plus (as anhydrous) based on its own weight, than most other carriers, but in addition, the plated calcium lactate can be effectively coated with a lipid wherein the lipid is less than 45% by weight of the final coated product. By "effectively coated" it is meant that the coating is sufficiently continuous to reduce the leach rate of the acid to that necessary to assure against the development of the so-called "hot spots". The present invention also means that a high acid concentration throughout the meat product can be obtained with the use of a minimum weight of acidulant.